dede field globe是什么？

Of course. Let's break down what the dede_field function is in DedeCMS (织梦内容管理系统), what it does, and how to use it. This is a fundamental concept for anyone working with DedeCMS templates.

What is dede_field?

In simple terms, dede_field is a powerful PHP function used within DedeCMS templates to retrieve and display the value of any field from a content record.

Think of it as a universal key that can open any "box" (field) in your article's data. Whether it's the article title, the author, the publishing date, or a custom field you added yourself, dede_field can get it for you.

Why is it called "globe"?

The term "globe" in this context is likely a direct translation of the Chinese term 全局 (quánjú), which means "global" or "universal".

The function is called dede_field because it can access fields globally from the current content record being processed by the engine. It's not limited to specific template variables like {dede:field.title}. It can access any field defined in the dede_archives table (for articles) or related custom tables.

The Basic Syntax

The function is most commonly used within DedeCMS's template loop tags, like {dede:arclist} or {dede:loop}.

{dede:field name='field_name' /}

• {dede:field ... /}: This is the opening and closing tag for the field function.
• name='field_name': This is the required attribute. You replace field_name with the actual name of the database field you want to retrieve.

How to Use dede_field: Common Examples

Let's assume you have a standard DedeCMS article. The main data is stored in the dede_archives table.

Example 1: Getting Standard Fields

These are fields that exist in every article by default.

• Get the Article Title:

  
  （图片来源网络，侵删）

  {dede:field name='title' /}

  This is functionally identical to the more common {dede:field.title /}.

• Get the Short Description (Introtext):

  {dede:field name='description' /}

• Get the Full Content (Body):

  {dede:field name='body' /}

• Get the Publishing Date (formatted):

  {dede:field name='pubdate' function='MyDate(@me)' /}

  Here, we use the function attribute to format the timestamp. @me is a placeholder for the field's value. A more common built-in format is strftime:

  {dede:field name='pubdate' function='strftime("%Y-%m-%d %H:%M:%S",@me)' /}

Example 2: Getting Custom Fields (The Power of dede_field)

This is where dede_field truly shines. Let's say you've added a custom field to your channel, for example, "Author's Website" (with the field name authorurl).

• Display the Custom Field:

  作者网站: {dede:field name='authorurl' /}

  If the field is empty, this will still render the text "作者网站: ". To avoid this, you can use an if statement.

Example 3: Using dede_field with Conditional Logic (if)

You often want to display something only if a custom field has a value. This is a very common and practical use case.

Let's display an author's website link only if the authorurl field is filled.

{dede:field name='authorurl' runphp='yes'}
if(@me != '') {
    @me = "<a href='" . @me . "' target='_blank'>访问作者网站</a>";
} else {
    @me = "";
}
{/dede:field}

Explanation of this code:

• runphp='yes': This attribute tells DedeCMS to execute the PHP code inside the tag.
• if(@me != ''): It checks if the value of the authorurl field (@me) is not empty.
• @me = "...": If the condition is true, it reassigns the value of @me to be the HTML link.
• @me = "";: If the condition is false, it sets @me to an empty string, so nothing is displayed.

Comparison with Other Field Methods

It's helpful to see how dede_field fits in with other ways to get field data.

Key Takeaways

1. Universal Access: dede_field is your go-to function for accessing any field from a content record in a DedeCMS template.
2. "Globe" = Global: It can access fields "globally" from the current data context, not just predefined ones.
3. Essential for Custom Fields: It is the primary and most reliable way to display the values of custom fields you've added to your content types.
4. Power with runphp: Combining dede_field with runphp='yes' gives you immense flexibility to format, manipulate, and conditionally display your data.
5. Know Your Field Name: To use it effectively, you must know the exact database field name (e.g., typeid, arcrank, your_custom_field_name). You can usually find these in the DedeCMS database or by examining the form when you edit an article.